The movie "Harriet" which came out last month stars actress Cynthia Erivo.
The conversation happened 25 years ago.
The movie's script writer, Gregory Allen Howard, said one studio head said, "This script is fantastic. Let's get Julia Roberts to play Harriet Tubman."
When someone pointed out that Roberts couldn't be Harriet, the executive responded, "It was so long ago. No one is going to know the difference."
When talking about the episode, Allen said the climate in Hollywood was very different 25 years ago.
Allen told the story in an interview posted by Focus Features, the Studio behind "Harriet."